Identification of the PLK2-dependent phosphopeptidome by quantitative proteomics [corrected]

PLoS One. 2014 Oct 22;9(10):e111018. doi: 10.1371/journal.pone.0111018. eCollection 2014.

Abstract

Polo-like kinase 2 (PLK2) has been recently recognized as the major enzyme responsible for phosphorylation of α-synuclein at S129 in vitro and in vivo, suggesting that this kinase may play a key role in the pathogenesis of Parkinson's disease and other synucleinopathies. Moreover PLK2 seems to be implicated in cell division, oncogenesis, and synaptic regulation of the brain. However little is known about the phosphoproteome generated by PLK2 and, consequently the overall impact of PLK2 on cellular signaling. To fill this gap we exploited an approach based on in vitro kinase assay and quantitative phosphoproteomics. A proteome-derived peptide library obtained by digestion of undifferentiated human neuroblastoma cell line was exhaustively dephosphorylated by lambda phosphatase followed by incubation with or without PLK2 recombinant kinase. Stable isotope labeling based quantitative phosphoproteomics was applied to identify the phosphosites generated by PLK2. A total of 98 unique PLK2-dependent phosphosites from 89 proteins were identified by LC-MS/MS. Analysis of the primary structure of the identified phosphosites allowed the detailed definition of the kinase specificity and the compilation of a list of potential PLK2 targets among those retrieved in PhosphositePlus, a curated database of in cell/vivo phosphorylation sites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Catalytic Domain
  • Cell Line, Tumor
  • Consensus Sequence
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Phosphoproteins / chemistry
  • Phosphoproteins / metabolism
  • Phosphorylation
  • Protein Processing, Post-Translational
  • Protein Serine-Threonine Kinases / chemistry
  • Protein Serine-Threonine Kinases / physiology*
  • Proteome / chemistry
  • Proteome / metabolism*
  • Tandem Mass Spectrometry

Substances

  • Phosphoproteins
  • Proteome
  • PLK2 protein, human
  • Protein Serine-Threonine Kinases

Grants and funding

This work was supported by Associazione Italiana per la Ricerca sul Cancro, AIRC (grant number IG10312) (to LAP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.